I keep writing about this since it’s a major problem for your concrete. Sealed or unsealed the salt water ruins any concrete. See attached pictures.
Pictures from a pool that water was changed back to bromine. Went right through sealer and acted as bad as road brine on a driveway.
This will be a costly unessary repair.
To date the only thing effective prior to sealing would be silaxane applied.http://www.split-rok.com